Wiring device



Nov. 14, .1944. .G.IB.BENANDER 2,3e2,794

WIRING DEVICE Filed April 11, 1942 Sheets-Sheet l w Aw L v v Inventor:

Geor- B. Benander;

Hi5 Attorney.

Nov. 14, 1944. BENANDER 2,362,794

WIRING DEVICE Filed April 11, 1942 3 Sheets-Sheet 2 70 24 7!! 34m 61 4 as o :11: I o

Inventor: George B. Benander,

His Attorney.

Nov. 14 1944. G. B. BENAl QDER WIRING DEVICE Filed April 11, 1942 3 Sheets-Sheet 3 m 5 PM m mm r he/Zm W t B A e .s M5 H o 9 e G b Patented Nov. 14, 1944 Q g umrso STATES PATENT OFFICE wramd nsvrcr:

George B. Benander, Oaklawn, B. 1., assignor to Monowatt Electric Corporation, a corporation of Connecticut Application a t-u 11, 1942, Serial No. 433,545 I 4 Claims. (Cl. 1'14-64) The present invention relates to wiring devices Referring to the drawings, each of th wiring of the type in which the device is part or the box devices has an elongated bas I and a cover 2 for enclosing the connections to the power conboth of which may be made of suitable molded inductors. Such wiring devices are particularly sulating material. The base is provided with adapted tosurface wiring systems. screw holes 3 for attachment to a supporting Since the device and box are a single unit it is surface and is narrow enough so that it can be desirable that the number of different devices reattached to the narrow edge of two-by-iour framquired for a'wiring system be kept to a minimum. ing whenused in an open wiring system. Along In the present invention only six devices are rethe sides of the base members are projections 4 quired, namely, a single pole switch, a three-way which are of diflerent sizes and which fit in correswitch, a duplex receptacle, a rosette or junction sponding depressions 5 in the sides of the rebox,,a lamp socket, and a lamp socket with a spective covers. The projections and depressions pull-chain switch. 4 and 5 insure that the covers are assembled with It is also desirable that the devices be capable and properly positioned on the bases for which oi use in wiring systems using metallic armored they are designed. At each end oi the device are cable, non-metallic cable (cable having a nontwo openings for armored power conductors. The metallic sheath or armor) and knob and tube openings are formed partly in the base and partly open wiring. In the metallic armored cable sysin the cover and are blocked by knockouts -6, l, tem, a continuous ground connection must be carand 8 of different sizes, one or more of which are ried through the metallic armor. In the present removed depending upon the size and type of invention this is done by means oi a ground strap power conductor to be connected to the device. used interchangeably with each of the devices Along the sides of the cover and base at each end and having clamps for holding the cable and main are knockouts 9 for use in open wiring. The ing the ground connection to the metallic armor. covers are attached to the respective bases by In systems using non-metallic cable or open wirscrews in threaded into sockets II in the base, in the ground strap is not necessary and its exand when assembled the base and cover serve as pense is eliminated. an outlet box for enclosing the device and its The object of my invention is to provide an connections with the power conductors clamped improved construction and arrangement in wirbetween the cover and base. ing devices of this type, and for a consideration when the wiring devices are used with meof what I believe to be novel and my invention, tallic armored cable, the ground connection to the attention is directed to the following description armor is made through a ground strap i2 having and the claims appended thereto. screw holes IS in line with the screw holes 3 in In the accompanying drawings, Fig. 1 is atop the base so that the ground strap and base are plan view of part of a surface wiring system using secured to the support by the same screws. The metallic armored power conductors and wiring baseis seated on the ground strap with its ends devices embodying my invention; Fig. 2 is a view confined between upwardly extending flanges I4 similar to Fig. l with the covers of the wiring deat the ends of the ground strap. At the top the vices removed; Fig. 3 is an exploded perspective flanges H are bent outwardly to provide horiview of the switch appearing in Fig. 1; Fig. 4 is zontal flanges l5 which are suitably indented at an exploded perspective view of the lamp socket it to provide the lower half of a clamp for gripappearing in Fig. 1; Fig. 5 is a top plan view of ping metallic armored cable. The upper half of part of a wiring system using non-metallic the clamp is provided by a clamping member ll armored power conductorsand wiring devices emhaving tongues I 8 slidable in slots IS in the flanges bodying my invention; Fig. 6 is a view similar to I5 and having to es 20 extending along t Fig. 5 with the covers of the wiring devices reinner faces of the flanges I 4. The upper clamping moved; Fig. 7 is an exploded perspective view of member I! at its top is provided with a tapered the convenience outlet appearing in Fig. 5; Fig. 8 recess 2| of the same shape as the tapered prois a perspective view partly broken away 01 the jection 22 at the ends of the base and cover so conductor clamps; 9 1 top plan view of the device may be assembled on the ground strap three-way switch with the cover removed; Fig- Without disassembling the clamp- The to u 10 is a bottom plan view of the pull-chain lamp 2!! which project inwardly beyond the extreme socket; Fig. 11 is an exploded view or the pullends of the base and cover serve to locate the chain switch; and Fig. 12 is an exploded perspecdevice on the ground strap. The clamping memtive view of the rosette or Junction box. bers are held together by crews 23 extending loosely through the center of the upper clamping member I1 and threaded into the center of the flange I5. The upper clamping member is indented at 24 and is provided with a flange 24a for more effectively gripping metallic cable. As shown more clearly in Fig. 2, the openings through the clamps are in line with the openings in the device.

In the single pole switch, as shown most clearly in Fig. 3, the base is provided with a hollow projection 25 housing the switch mechanism which need not be illustrated for the purposes of the present invention. Across the open top of the hollow projection 25 are a strip of insulating material 28 and a metal strap 21 fixed by screws 28 to the ends of the projection 25. The strap 21 is provided with a slot 28' through which the switch handle 29 of molded insulating material projects and is provided with arcuate seats 39 on each side of the slot 28 pivotally engaged by projections 3| integral with the switch handle. The switch handle accordingly is pivoted on the strap 21. At opposite ends the strap 21 is provided with terminal screws 32 so that the strap, which is insulated from the switch, may be used as a bus bar. At one side of the base is fixed a conductive strip or bus bar 33 having terminal screws 34 at opposite ends and at one end having an integral arm 35 (Fig. 2) connected to one of the switch contacts inside the projection 25. The other switch contact is connected to a strip 36 carrying a terminal screw 31 which is on the opposite side of the base from the terminals 34.

The switch terminals 34 and 31 are accordingly on opposite sides of the base, and the mounting strap or bus bar 21. which is insulated from the switch terminals and is used to eliminate the need for a jumper extends lengthwise of the base at the center. The switch handle 29 projects out through a slot 38 in the cover.

When the switch is used to control a device at the end of a power line, as shown in Figs. 1 and 2, the ground conductors 39 and 49 are connected by the terminal screws 32 to opposite ends of the strap 21. The incoming live conductor H is connected to the terminal screw 34 at one end of the switch, and the outgoinglive conductor 42 is connected to the terminal screw 31 at the opposite end. The circuit between the terminal screws 34 and 31 is respectively made and broken in the on and off positions of the switch.

The three-way switch (Fig. 9) is of the same construction as the single pole switch previously described except for the substitution of a threeway switch mechanism. Corresponding parts bear the same reference numerals. The threeway switch mechanism (which may be of any suitable construction) is mounted in the hollow projection 25 and is operated by the handle 29 which projects through the metal strap 21. The switch is provided with terminal screws 99, 9i, and 92 respectively threaded into strips 93, 94. and 95 connected to the three-way switch. By operation of the handle the terminal 99 is connected to either the terminal 9| or the terminal 92. It will be noted that the metal strap 21 is available for use as a bus bar to feed a circuit through the device without the use of a, jumper.

In the lamp socket, as shown more clearly in Fig. 4, the base I is provided at the center with a cylindrical projection 43 on the upper end of which is mounted a screw shell 44, and tlfe cover 2 is provided with a cylindrical projection 45 surrounding the upper end of the screw shell. The

screw shell is fixed on the upper end of the pro sides of the base.

jection 43 by screws 49 threaded into the projection through a flange 41 at the bottom of the screw shell. Integral with the screw shell is a metal strip 49 connected to a terminal strip 49 by means of a screw 59 threaded through the strips 48 and 49 into the base. The strip 49 at opposite ends is provided with terminal screws 5I. Within the screw shell is a center contact 52 fixed to the upper end of the projection 43 by a rivet 53 which connects the center contact to one end of strip 54 on the under side of the projection 43. The other end of the strip 54 is connected by a rivet 55 to a terminal strip 56 provided at opposite ends with terminal screws 51. The socket terminal screws 5I and 51, like the switch terminal screws 34 and 31, are at opposite At the center of the base is a terminal strip or bus bar 59 provided at opposite ends with terminal screws 59 and extending up over the top of the projection 43 through a groove 99. The bus bar 58 extends beneath the screw shell 44 and center contact 52 and is insulated therefrom by a strip of insulating material BI in the groove 99 on top of the bus bar 58. 'The bus bar 59 eliminates the need for jumpers in the same manner as the bus bar 21 in the previously described switch construction. In the wiring system shown in Figs. 1 and 2, the ground conductor 49 is connected to one of the terminal screws SI, and the live conductor 42 in series with the switch terminals 34 and 31 is connected to one of the terminal screws 51.

The lamp socket may be provided with a pullchain switch (Figs. 10 and 11) arranged in a cavity 96 in the under side of the base and having contacts 91 and 98 respectively connected to the lower ends of the rivets 53 and 55. The cavity may be closed by a plate of insulating material (not shown). The contacts 91 and 93 rest on alternate ratchet faces 99 molded in the base. The circuit between contacts 91 and 98 is alternately made and broken by a bridging member I99 on disk I9I rotatable on a spindle I92 threaded into a hole I93. The bridging member has arms I94 projecting through slots I95 in a disk of insulating material I98 and terminating in contacts I91. The bridging member is rotated in a counterclockwise direction (Fig. 11) through successive on and off' positions by a member I99 having ratchet teeth I99a cooperating with notches I99 in the disk IN. The member I9! is biased in a clockwise direction by a coil spring I I9 having opposite ends hooked over a tank III on a washer II2 non-rotatable on the head of spindle I92 and over a tang II3 on the ratchet member I98. The member I98 is rotated in a counterclockwise direction by a pull-chain II4 extending out through a suitable opening in the side of the base.

In the wiring system shown in Figs. 5 and 6, the power conductors have a non-metallic sheath or armor and, accordingly, the ground strap is unnecessary. The switch and lamp socket there illustrated are of the same construction as previously described and bear the same reference numerals. In addition there is shown a convenience outlet which will now be described.

The base I of the convenience outlet has a projection 52 at each end of which is a pair of U- shaped walls 53 receiving terminals 94 and 54a for connection with the prongs of an attachment plug inserted through openings in the cover. The terminals 54 and 94a are respectively integral with terminal strips 55 and 91 fixed to the pro- Jections 52 by screws 58 and equipped respectively assay with terminal screws 35 and II. The terminal screws 33 are for connection with the ground conductor, and the terminal screws 13 are ior connection with the live conductor. Extending along the base between the terminals 44 is a bus bar or terminal strip II having terminal screws I2 at opposite ends. The bus bar" is seated in a groove I3 in thebase and is held therein by a strip of insulating material I4 which is clamped under the terminal strips 33 and 31. The bus has II eliminates the need for jumpers in the same manner as the bus bars 21 and 53 in the previously described constructions.

In the wiring system shown in Figs. 5 and 6 the switch is used to control the circuit to the convenience outlet and the .power circuitis fed through the switch and convenience outlet to the lamp socket. The ground conductors I3 and I3 are connected by the terminal screws 32 to opposite ends of the switch bus bar 21. The incoming live conductor I1 is connected by terminal screw 34 to one end of the strip 33. The other end of the strip 33 is connected through the other terminal screw 34 to a live conductor 13 of a three-conductor cable 13. The other end or the conductor 13 is connected by the terminal screw I2 to one end of the bus bar II. The remaining conductor 30 of the three-conductor cable is connected atone end to the switch terminal screw 31 and at the other end to one of the convenience outlet terminal screws Ill. The power circuit to theconvenience outlet, which consists oi the conductors I3 and 33 of the three-conductor cable I3, is accordingly controlled by the switch. The lamp socket is fed by a cable 3| having a ground conductor 32 connected to the remaining ground terminal screw 69 of the convenience outlet and a conductor 33 connected to the terminal screw I2 at the other end of the bus bar II. The conductors 32 and 83 are respectively connected to the ground and live terminal screws 5| and 51 of the lamp socket. V

In the above described construction the power is fed through the switch terminals to the convenience outlet and is fed to the lamp socket independent of the switch terminals.

It is also possible to use the switch in a circuit in which the switch is beyond the load, as would be the case if the power were fed into the circuit through the cable 8|. The connections would be as illustrated. The ground circuit would run from conductor 82 through terminal screws 63, conductor "I6, terminal screws 32 and strap 21 to conductor 15. The live circuit to the convenience outlet would run from conductor 83 through bus l3 and conductor 13 to switch contact 34 and from switch contact 31 back to the convenience outlet through conductor 33. The live circuit "would be fed beyond the switch by conductor I! connected to the terminal strip 33.

The device shown in Fig. 12 may be either a or which is below the center terminal screws Illa and l2la. The drop center construction or the bus bar I2I provides ample clearance between the bus bar and terminal screws Illa and Illa to which conductors would be connected when the device is used as a rosette.

In each or the above described wiring devices the device and its enclosing box comprise a com- The use of thedevices is further simplified by the conductor clamping arrangement having knockouts 3, I, and 3 for use with #12 and #14 two and three conductor metallic and non-metallic armored cable and knockouts 3 for use with #12 and #14 open wiring. The knockouts 3, 1, and 8 are spaced apart along conductor receiving grooves 34 at each end of the base I and cover 2.

The knockouts 3 are at the outer ends of the grooves and have surfaces 33 for gripping two conductor non-metallic cable in sizes #12 and #14. The knockouts I are arranged in channels 33 transverse to the length 01' the grooves 34 and have surfaces 31 projecting above the grooves 34 for gripping three conductor non-metallic and B. X. cable in size #14 and two conductor B. X.

rosette or a j nction box, depending on whether or not a knockout H5 in the cover is removed. At opposite sides of the base are terminal strips H3 and Ill fastened thereto by screws H3. The terminal strips are provided with terminal screws H3 and I23 at opposite endsand terminal screws I 19a and I230. at center. At the center of the base is a bus bar IZI having terminal screws I22 at opposite ends arranged in notches I23 in bosses I24 which separate the terminal screws H3 and I20. The terminal screws I22 are somewhat higher than the other terminal screws. Between the terminal screws I22 the bus bar I2l is bent to provide a U -shaped connecting portion the base in sizes #12 and #14. The knockouts I may be removed by a screw driver or similar prying tool inserted into the space between the knockout and the sides of the channel 33. The knockouts 3 have thin removable sections 33 at the inner edges of ribs 39. The sections 83 form closures for the grooves 34 and when removed provide sufllcient space for leading the conductors into the device as illustrated in Figs. 2 and 6. The grooves 34 are shaped to properly grip the largest conductors (three conductor #12 non-metallic and B. X.) for which the devices are designed. By removing one or more of the knockouts 6, I, and 3, the device may be used with the customary sizes of armored cable. clamp is required other than the selective removal of the'proper knockouts.

Certain features disclosed are not claimed herein as they form subject matter of my two divisional applications Serial Numbers 531,797 and 531,798, both filed April 19, 1944.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. In a wiring device for wiring with a plurality of conductor sizes, mating parts of insulating material enclosing the device and having formed therein a. clamp for armored conductors of different sizes, said clamp comprising a conductor receiving groove in said parts and a plurality of knockouts spaced along said groove, said knockouts having conductor gripping surfaces projecting different heights above said groove and respectively shaped to serve, prior to removal, as clamps for different conductor sizes whereby the clamp may be conditioned for a larger conductor size by removing the knockout for a smaller conductor size.

2. In a wiring device, a part of breakable insulating materia1 having a conductor receiving groove, a channel in the walls of the groove extending transversely to the length of the groove, and an integral knockout in the bottom of the No adjustment of the conductor channel having a portion projecting above the walls of the groove, said knockout being spaced from the sides of the channel so it may be broken out by a tool inserted between the knockout and the channel.

3. In a wiring device, a conductor clamp oi breakable insulating material having a conductor gripping surface, a channel in said surface, and a knockout joined to the clamp in said channel and spacedfrom the sides 0! the channel so it may be broken out by a tool inserted between the knockout and the channel and projecting above the channel, the projecting part 0! said knockout being formed to provide a conductor gripping surface prior to its removal.

4. In a wiring device for wiring with a pluralit of conductor sizes. a split conductor clamp having mating parts of insulating material provided with a conductor receiving groove, a knockout at one end or the groove closing the same, a knockout at the other end of the groove partially closing the same projecting to a height above the groove and shaped to provide, prior to its removal, a conductor gripping surface for one of the conductor sizes for which the device is adapted, and a knockout intermediate the other knock outs projecting to a lesser height and shaped to provide, prior to its removal, a conductor gripping surface !or one of the larger conductor sizes for which the device is adapted.

GEORGE B. BENANDER. 

